SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd691441518b431fa21dba4a73243ffafa6541bf4c453a339e69cb44dc914b383' 
  AND token = '0NC2Bv3URgGe1azvmnsBwW3iCLuKq/h8kCF2vPg0G8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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