SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '027c02918de9c59d3cd44be8a363b95cb306bdda045da3780338769dc497fbb7' 
  AND token = 'IUoe92A0vUaBI8pxYlnynKqXIglcE7TmpjIs5u2S6qI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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