SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ba564766c1517e613c34c7d18f96643e263c89e1dac38f2e6381bc122ee40b94' 
  AND token = '3ssGcwjGCGLBD+WCSEG9gdOwXw9sdBYmqShD2jjWFtU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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