SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8e2b7852cd3f2573c1e30285c4d4c7016339be75a634f88611acb23500df3e6b' 
  AND token = 'em2Cj7swKRijZXQPL1qJ5DpI1i+/86zUEXqZmEBaI/8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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