SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e0a579ddaaf720202df9cf462278cafe70f90d2d88c7a245c8586510360fc8ab' 
  AND token = '+K/6gIUlhBeJmPN61NFgh57X7nHdPzfYt0+q7pIOrFA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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