SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4729f8a57cf93d0fe9c609202356050881352567316dae8a0ec6b32d655e16ac' 
  AND token = 'M+icdXpEygbzR5sgAVYdnJNQDSeAcTmEKA4CLF0tsT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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