SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68b320d9516df217e18f7de04048ba01e29fbbeaceaaedd05a57493cc6480029' 
  AND token = 'qnDbmezKxYZ7vHtAGXMyf8Zuc+LdwdZx6mQlJPb7i1U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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