SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f053c640828a166b3fe43f9fcfad143c39927c87ca3717a424b2a701e8ed7a38' 
  AND token = '3Nqv3hDGt2WpqsnccQKaCWgF+JV+7MVHWO/cqUctfqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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