SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '432dd0779c69044f5a1f3b9c0afb468fc325cf445f89d51d1247b0a6f3f74410' 
  AND token = 'y7tTXdklsrGXjzRqpGEpUFi11grXL3fWbndKvXIwUuM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}