SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88c686df95b61bb45ca13f5077672fe763364d42f097bc772ec100fe9923cedc' 
  AND token = 'evsBrbUhJ7yGYIvMDpNiw9QoTq5ICmhAdo7z21zc45Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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