SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57f9357fce0314efb25c9c41afccc61ffd4fbb22f11f0015218bf6135138671a' 
  AND token = '/7mK7Jua4Ywz9Qx1dPKOOdgyjWOlYMIDPRLGweXstu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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