SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0ba628c30299bfbd1f64e424ca5c372590e9a227f87a4b910279b3b6cce66a42' 
  AND token = '4qox+8vuTConX2voR+BBt/Ei97r8AhyDVxNZmZQAm2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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