SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '090a4bb1d311a285d5b546b5ffffa8da353711986e58bebe2a6437a81274e4f7' 
  AND token = 'q4sH/Lzt998jBD+vqpGfRgnGuPWn+rkJkgmxrV31rHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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