SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '988fd1b87411572da2e60a7fc9b2ffc6e388834fb1f98acbcf2c4ccc2ae9654c' 
  AND token = 'LGoNKAsSOVXQV99HqWsx+/Jukzu+vuRiCp/apHRocW4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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