SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49836a4cbdea74188144f20a7112de0cb0bfd82b21d76006878b3d1d667371fe' 
  AND token = 'zT+zt3ZuHllCgoSXJevA1NPP3QRi3nrWjomNAsJVdSU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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