SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '46021daee1914e76a495dd791e5a4c02c14888a4e93f229767fb04db2c6abca7' 
  AND token = 'eTK5vw/iFKE2CpiR/+b/1kMT47G4xHJUmbAH8AUO6Mg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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