SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6cc081abca5d6a03fc9e9bd774672a55b43b6927c8152da1b8d42ce883e5e645' 
  AND token = 'PKxvmCJQgwoiCxAb0sYgdPqRIBU6j+QPIVzDsQYLg9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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