SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c585935aa3c0ea68cf50c2962963a1efa21e8fac5c096199fa6c2d8ac3cc1281' 
  AND token = '7wDnbjjRplR5iCLrbJQbyUQqLnTIvyJDNb1KUjAylkU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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