SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27ac657fcafeef5b8844b886bdf8ebd1d2ea795e8c89cb405e806eddb3c003d4' 
  AND token = 'VKPwSgr8WeWPCeVOWfpdeZM7KRaVtm+33fLkzffTTek=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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