SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c64e85574e0b3795b27fb362bbefe7d1b64efafdc979d838f94ef8a62d9b109d' 
  AND token = '0TmqnBW5fGZCwVFNaWO131kbecEiC51llQe0KBIxYlk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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