SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bcce4eb282d697691804ff8f8721ae552e119170adbb862b0581099588a399d' 
  AND token = 'wkOAwT7oj81jRZebtQwY/NSGAhV1kdxz1Z+WBg8QYyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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