SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '582515b1cf73f6b9c3109e2f3890f8f377cd9a66837bd2aa7b8519c984a4984b' 
  AND token = 'lXLukKuvpKvD0j2c3+pTpV7lbTMzvPvTL/QQsYY5IPM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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