SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '994a88b151758b7b7fb2071d054e06b75c6b548450d99b78609f8401226641c9' 
  AND token = '+zGRh97KDVdYqZP7BkHmYOs+ODebwxXKATQvt2hYFy4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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