SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '99bb1ef4fe326b56b0c00a9b95f2df1d79dacaf51aadc3eb1a6d0bba313f433f' 
  AND token = 'irevkjLreDATjRwauA8Y6pstbmAB98jmSagDZaVrHyI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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