SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4ab8cac41a98e854e48690eab0890c192a8ae4c12789ca7aed99c1b47c823ffe' 
  AND token = 'urXPvXgNtM/SaZ+pf2ReK86zhFUzBUkMvLKBs2IQvwE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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