SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c19a81fc3b866dbe8546e77aea865d3ce45555a46fe73d9e933725666bfb3f25' 
  AND token = 'ASRI3UFqWzOH8q4Cr+l3AAousCKtGerEMVBpBEmPuBo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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