SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd3ef7b5251376ad47d8872b78f7ba05d35a342e5d2fbc56623e73d09a5fd842f' 
  AND token = 'rvnLcWSQ0FpSWhhIK2B3quBArLYvYaKBpJp9T7bDuzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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