SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4598cfb320c728108921341c71fbfb22b729f6d2d97ed3c7caaa2aabb6677991' 
  AND token = 'SF8/4EglXGIHVjHBoQQ+OzSY+tkovb42QhDn+kTOVjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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