SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c37c6311600243c5dbf7a6530227aa8312aa6c96c2bee551928f070cafbbea79' 
  AND token = 'Bl7RTJ5Gtr5oIMcC01NFJN2zjMiZDAARySOEvQ5UiGo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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