SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a14d4010a32401048b0d265664a185de09abe0fe3d0f85c7edc8f498295ae495' 
  AND token = 'lnB7iRV19HGYrWfdCSDmwVKKFl46ekwFOue+tWbPdgM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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