SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '754d4d2d165532f57a5ec3a61e33897f4daeb225b3480b19001df96f07c122d8' 
  AND token = 'mKLRDLr6hC4NtRZPeGDN/hXVGg9EMZzDjU2/u5ZHeYM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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