SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '30403dd3e43cc2f00cd6a35a370201c19dc46515af47bbfcd56dd78a4a9c8acb' 
  AND token = 'N66tfTaWml8mB7TZluac08O937KMASAFpP+uk2yWxS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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