SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28d7ab1e75e90d81678167c754b1320e5088bb1a290dbb6e9cff28731540be80' 
  AND token = 'cYTzq4qY8dJ7iehl85lYEcTPYDR6GQ1ddPBHju3Xf5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}