SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '657783600e9d955f71bed4b242eb892e541004b82dd9f804f922375921963f9b' 
  AND token = '4rhpWTvchRae8+Z8WXR65sPYpxfIXdVnDL9a52T0rTo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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