SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d1d25ff21919d5d7956b35906bd9391d43d7ed3049e2fa258e4936e58b36049' 
  AND token = '6F3Of6Cu9BRXOheL256rXWJlCKPK2K1xIlOOFH/j/Wk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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