SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9603dadf50f498302ad78aa959ae7ed4f64b84c559eaed76dbb12d9a4c3546b6' 
  AND token = 'BgnGca7Uq3SOQozo3Alx2EEyBqdU6Jwclk0FJzEZcxE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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