SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80442bfc43fc1b6ef25afed28a765774522227ac37a24defef60c08fa51e9e74' 
  AND token = 'HgberGB0dTNr4qyaG8riFlvkKssjzg20KiXiDizDKW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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