SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f63c17b4949851f52ccf0ce7839099cb9c6150caf38c2b8fdf34ef46893f5272' 
  AND token = 'u2woG1J/diZrdFPJ5AS9wSQJbO9YUvWd2f1+eBJQiNM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}