SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'e97edff441e51ef34d02dbdc6f0b337818884792c241a8bba4749ce39bd2b038' 
  AND token = 'gmjSb7hIDQtkpnXVUPr9y/+ca/LLwHPEmRH6rKZiFsw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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