SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fd8818ddfbf88d6acdbdb8426ce855f4badd2843e3b7941d8123f248e01b3396' 
  AND token = 'Ty+ba5Iwy27k3DBl2kgYA4P8V7dOItn4NbhwdsJlLBI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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