Sandbox

SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '6c055de559c1a18488e7847f4a7bcd5f839d6bba9cd832e7d98aedf73baa537b' 
  AND token = '0OuCYxI1AQ28ppOI0qvDJduL7LmaoBCnlZFcMPpxZXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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