SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ab8660258f0507a41c61437729ad093f460a2c668524de1ad34c97d4671ff1df' 
  AND token = 'JfzKFGZ3ZXkRDmCeMPetI+jhSxcChjybMHasF/xji4s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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