SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dec7386b5131f97a731cb5a35c4b67fddc151e96071d370c5209ecd0555b4cf2' 
  AND token = 'VXzdkq29ztxvICi2qAIIxxtKXGDIhly6vRcH6ucrk3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00058

JSON explain

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