SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6656df4ba9043ba1b8669f068dfa5a3803e03f767ea978946284e8fda6c06a5f' 
  AND token = '6MYutdzoo2wr287TezODXhDKIbVJWUJyTCC0n3cZsVw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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