SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf84399ed13c8aab43d452bd774bb8a13f7c95d07ab3dfa01fcbf6e990641620' 
  AND token = 'pQhLxic1w/4scoR+6vVBcoDGaw3OHBigFVIE5zX9gHw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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