SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c314a92a23c8a7f98e187e07e1b1673646d217a45bd25b5b6a2c457563ffc2a0' 
  AND token = '9hB1Qb6syz3sGCMHzGYpMX+IfkbKVDVbtKn8hQWoHYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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