SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '04a7b448324f83f8324b97518c420f831eb65c933a609714a0e2108c8799cccc' 
  AND token = 'Ebx+lTNkOdVcbHXtcePqKD36XCeg6ZPEtML3j+tDEak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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