SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ce2efafeeb00892ffb8cc1255e9039b88c996d57f8e53b5a76db86174c9c78eb' 
  AND token = 'xSiAqnV995PdBpQVbz3JDHlWLYKnGoEXoIQh2ZAROsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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