SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a62cfab6bb317bef1752015a395359c0696306270c1d7289f9be1d66d73942ed' 
  AND token = '7uCenhzZ795BncE2jJNGoMqDIsKFGx+RMDXfz/H2GdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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