SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f98cd160528fb9cf1cd22aeef5ff90e6e5279be960470013710266884efc456' 
  AND token = 'DisGnbMSJhFdZKXuEHMHTcRcZRc9pgSFyZ3ppVql25o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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