SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3ea3ecaae6583d962f2778f7a531b4b94d3bbe41f8a6828c0b4ad3a68289606' 
  AND token = 'SZqfyuWANfuaO14O5yH3IRE1ryEB25Lk9ZcCp3RLpCw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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