SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '655897c1000c8598f9164f04ad986bdbd0201b295d970169bad7fa6e56dd3369' 
  AND token = '2/JkzCENbWwpLyvEojQvS6Ifqd9/C7VPWECz+xsJLhk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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