SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '372ef2d51122cdcfb9d25d43c3a9138966e6d7051f4dccc274fcb71dfb1cec9c' 
  AND token = 'FUepggl7xJvyzODbHHg9WPGmdBFF+bLXNxJ8MVW0tYg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00056

JSON explain

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