SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7345bb8194e4bc0f8aeba8ace3746705e958731d35b2d2d9e816e7b4ec6dff1' 
  AND token = 'hOZa/KhpgoRlvP1lIKm+1skxDRMzOwWkneqkv/lSVqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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