SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd53611c25d7566ed756a81fab1413288792a9706dd7813a5910937b3e04b3df9' 
  AND token = 'k7rUx3Ezn9PzfDbsGjeIKCS0Une2gzzk1MChyYOMZBU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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