SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '623cc3ecb604ffbdb3eda5bd9d9cea060b98ee9219e40e448422913e1d3720fa' 
  AND token = 'jLMW1ubcuk63Mb/04gghI8sPbfw4SdqDUU9cHJ48wYA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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