SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9953b8267e366a4064e8b29b2d84a30bd551fbdb8c47bcda289d4d3b095542cc' 
  AND token = 'qC/uJvBHMLrlc+ulO+E2HdV5WUlYSYV2EKgfRgNsEeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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